KR100567504B1 - Manufacturing method for reflector - Google Patents

Abstract

By coating and firing, a flat organic insulating layer 18 is formed on the substrate 14 having the thin film transistor 16. Next, a pulsed laser beam is irradiated to the organic insulating layer 18, and contact holes 18a and unevenness 18b are formed in and on the organic insulating layer 18 by ablation. The unevenness 18b is formed to have four or more height levels.

Non-transmissive, Reflective Film, Liquid Crystal

Description

Reflective film manufacturing method {MANUFACTURING METHOD FOR REFLECTOR}

1 is a diagram showing a cross-sectional structure of a liquid crystal display device according to a first embodiment of the present invention.

2 (a) to 2 (d) show manufacturing steps of the reflecting film according to the embodiment.

3 illustrates the structure of an optical processing system;

4 shows a profile of a flat top type laser beam.

5 shows a profile of a laser beam passing through a mask;

FIG. 6 shows a profile of a spot-shaped laser beam. FIG.

Fig. 7 is a diagram showing a cross-sectional structure of a reflecting film according to the third embodiment of the present invention.

8A to 8D are views showing manufacturing steps for manufacturing the reflective film shown in FIG. 7.

9 shows a profile of an irradiated laser beam.

♠ Explanation of the symbols for the main parts of the drawings.

10 liquid crystal display device 11 lower substrate

12 opposing substrate 13 liquid crystal layer

14 insulation board 15 insulation protective film

16: TFT 17: passivation film

18 organic insulating film 19 reflective electrode

20 gate electrode 21 semiconductor layer

22: drain electrode 23: source electrode

29: transparent insulating substrate 30: color filter

31 transparent electrode 32 polarizing plate

Background of the Invention

Field of invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflective film having excellent reflective properties, a liquid crystal display device having the reflective film and having excellent display properties, and a method of manufacturing the same.

Description of the related technology

Background Art A reflection type liquid crystal display device having a reflection film therein that reflects incident light to provide display light is known. Reflective liquid crystal display devices do not require a backlight as a light source. Therefore, the reflective liquid crystal display device has advantages such as low power consumption and thinning as compared with the transmissive liquid crystal display device. Because of this feature, the reflective liquid crystal display device is used for a portable terminal and the like. In addition, so-called transflective type liquid crystal displays, which have both reflective and transmissive characteristics, are also used in cellular phones and the like. The problem of the reflective liquid crystal display device will be described below, but the non-transmissive liquid crystal display device has a similar problem.

The reflective liquid crystal display device includes a liquid crystal filled in a liquid crystal cell, a switching element for driving the liquid crystal, and a reflective film provided inside or outside the liquid crystal cell. The reflective liquid crystal display device is, for example, an active matrix liquid crystal display device using a switching element such as a thin film transistor.

BACKGROUND ART As a reflective liquid crystal display device, a liquid crystal display device in which a concave-convex shape is formed on a surface of a reflective electrode has been developed to improve visibility. When the reflective electrode has a concave-convex surface instead of a flat surface, the reflective electrode reflects incident light in multiple directions. That is, by forming the uneven shape on the surface of the reflective electrode, display characteristics such as wide viewing angle are improved.

Although the uneven shape of the reflective electrode improves the scattering characteristics of the reflected light, the screen darkens due to the interference of the reflected light when the uneven shape is very regular. Therefore, in order to prevent interference of light, it is preferable to form irregularities as irregularly as possible.

As one method of providing the uneven shape on the surface of the reflective electrode, a method of forming the uneven shape on the surface of the insulating film has been developed. In this method, a photosensitive resin film is first formed, exposed using an exposure mask and then developed to form a discontinuous convex pattern. Thereafter, the surface of the film is dissolved by heat treatment to form a gentle shape. An organic insulating film is then formed on the resin film, and then etched for the contact hole. Finally, a reflective electrode is formed on the insulating film. The uneven shape by the resin film and the insulating film is formed on the surface of the thus obtained reflective electrode.

According to the above-mentioned concave-convex shape forming method, the concave-convex of the insulating film is formed to a substantially constant height. That is, since the protrusions of all the resin films have almost the same height (thickness) values, the height of the unevenness has almost two values. Here, the height of the unevenness means the difference between the height level (depth) of the top and bottom of the unevenness in the normal direction of the reflective film.

Another method using a so-called halftone mask has been developed, which is disclosed in Japanese Patent Laid-Open No. 2000-250025. According to the above method, the resin film is patterned using a halftone mask having different transmittances in the masking area. As a result, the protrusions are formed with different height values. However, the number of height values is two, and therefore, the height of the unevenness formed on the insulating film has three values.

As described above, in the related art, the height of the unevenness is set to have three values at most. Therefore, the uneven shape of the conventional reflective film has a relatively high uniformity and is monotonous.

The high uniformity of the uneven shape does not provide good reflection and display properties. Therefore, the conventional reflecting film in which the number of available values of the height of the unevenness of the insulating film is limited cannot sufficiently improve the display characteristics.

In addition, the above method of forming irregularities on the insulating film requires a relatively large number of processes, namely, formation of two organic films (resin film and insulating film), and exposure and development. In addition, the unevenness formed using the photolithography technique has a sharp shape and thus requires heat treatment to smooth the surface shape. Thus, conventional methods using photolithography techniques have the disadvantage of having a large number of processes.

As described above, the conventional reflective film has a problem that the reflective electrode cannot achieve sufficiently high reflective characteristics because the reflective electrode has a uniform shape, in particular, a relatively high uniformity. In addition, this method of manufacturing the reflective film has a problem that requires a relatively large number of steps.

In view of the above situation, it is an object of the present invention to provide a reflective film, a liquid crystal display device, and a reflective film manufacturing method having excellent reflective properties.

It is another object of the present invention to provide a reflective film, a liquid crystal display device, and a method for manufacturing the reflective film, which can be manufactured in a substantially small number of processes.

In order to achieve the above object, the semi-finished film manufacturing method according to the first aspect of the present invention,

Forming an insulating layer (18);

Irradiating the insulating layer (18) with a laser beam to form irregularities (18b) on the surface of the insulating layer (18) by ablation; And

Forming an electrode 19 on the insulating layer.

In this case, in the ablation step, the laser beam is irradiated onto the insulating layer 18 with a predetermined intensity distribution.

In this case, the laser beam is irradiated onto the insulating layer 18 through a mask 43 having a predetermined transmittance distribution.

In this case, the laser beam incident on the mask 43 has a flat profile.

In this case, scanning irradiation is performed with the laser beam having a spot shape.

In this case, in the ablation step, the laser beam is irradiated in a pulse shape.

In this case, in the ablation step, the unevenness 18b is formed to have four or more height levels.

In this case, the switching element 16 is provided below the insulating layer 18,

A contact hole 18a exposing one end of the switching element 16 is formed in the ablation step.                         

In this case, in the ablation step, a flat portion is formed on the insulating layer 18 together with the unevenness.

And forming a transparent electrode (52) on the flat portion.

The manufacturing method may further include annealing the insulating layer 18 after the ablation step.

In order to achieve the above object, the reflective film according to the second aspect of the present invention is:

An insulating layer 18 provided on the substrate 14 and having a plurality of stages of unevenness 18b having at least four height levels on its surface; And

It includes an electrode 19 provided on the insulating layer 18.

In order to achieve the above object, the liquid crystal display device according to the third aspect of the present invention is provided with the aforementioned reflective film 11.

Preferred embodiments of the present invention will be described in connection with the accompanying drawings. The embodiments of the present invention which will be described below are exemplary and are not intended to limit the present invention.

First embodiment

The liquid crystal display device according to the first embodiment of the present invention is an active matrix liquid crystal display device having a switching element such as a thin film transistor for each pixel.

1 is a cross-sectional view of a unit pixel area of the liquid crystal display device 10 according to the first embodiment. As shown in FIG. 1, the reflective liquid crystal display device 10 includes a lower substrate 11 constituting a reflective film, an opposing substrate 12 aligned to face the lower substrate 11, and the lower substrate 11. ) And a liquid crystal layer 13 sandwiched between the opposing substrate 12. The lower substrate 11 includes an insulating substrate 14, an insulating protective film 15, a TFT 16, a passivation film 17, an organic insulating film 18, and a reflective electrode 19.

An insulating protective film 15 made of an inorganic or organic insulating material is deposited on the insulating substrate 14. The TFT 16 functioning as the switching element is formed on the insulating protective film 15.

Each TFT 16 has a gate electrode 20 formed on an insulating substrate 14, a semiconductor layer 21, a drain electrode 22 and a source overlying the gate electrode 20 with an insulating protective film 15 therebetween. An electrode 23 is provided. The drain electrode 22 and the source electrode 23 are connected to an unshown drain region and a source region of the semiconductor layer 21, respectively.

The passivation film 17 is made of an insulating film such as, for example, a silicon-based film. The passivation film 17 is provided to cover each of the TFTs 16 except for the portion where the contact hole 18a to be discussed below will be formed.

The organic insulating layer 18 is formed on the passivation film 17. The organic insulating layer 18 is made of an organic material which is easily sublimated by laser ablation, which will be discussed below.

"Laser ablation" is a phenomenon in which when a laser beam of a predetermined wavelength range is irradiated to an organic material having an absorption band in a predetermined wavelength range, chemical bonding of the organic material is broken and the irradiated surface layer is lost (removed).

In other words, the organic insulating layer 18 is formed of an organic material that absorbs a laser beam of a wavelength used for ablation. The case where the organic insulating layer 18 is formed of polyimide resin will be described below.

A contact hole 18a is formed in the organic insulating layer 18 to expose the source electrode 23. The unevenness 18b is formed on the surface of the organic insulating layer 18. The unevenness 18b and the contact hole 18a are formed by laser ablation which will be described later.

The unevenness 18b of the organic insulating layer 18 is formed such that its height has various values. The "height" of the unevenness 18b is the height of the upper part or the bottom part with respect to the predetermined position in the normal direction of the reflecting film. In this embodiment, the position (thickness of the organic insulating layer 18) of the organic insulating layer 18 before the formation of the unevenness 18b is taken as a reference.

As shown in FIG. 1, the unevenness 18b of the organic insulating layer 18 has various heights within a predetermined range, in particular, a height value of 4 or more. In the case where the organic insulating layer 18 is formed to have a thickness of 3 µm, the height of the unevenness 18b has a height value of 4 or more within a range of, for example, 0.04 to 2.1 µm.

The reflective electrode 19 is formed of a metal such as aluminum or chromium in a predetermined thickness on the organic insulating layer 18 including the contact hole 18a. The reflective electrode 19 is connected to the source electrode 23 of the TFT 16 via the contact hole 18a and functions as a pixel electrode and a light reflecting layer.

The uneven shape resulting from the unevenness 18b on the surface of the organic insulating layer 18 is formed on the surface of the reflective electrode 19. Since the unevenness 18b of the organic insulating layer 18 is formed to have various height values and to have multiple stages, the unevenness formed on the reflective electrode 19 also has a plurality of steps and low regularity. It is formed to have. Thus, the light reflected by the reflective electrode 19 has a high scattering characteristic that provides a high reflection characteristic to the lower substrate 11, and as a result, a good display in the liquid crystal display device 10 having the lower substrate 11 Provide the characteristics.

The opposing substrate 12 includes a color filter 30 and a transparent electrode 31 which are sequentially stacked on one surface of the transparent insulating substrate 29. A sheet polarizer 32 is provided on the other side of the insulating substrate 29.

The liquid crystal layer 13 is twisted nematic (TN) type, super twisted nematic (STN) type, single sheet polarizer type (Guest-Host) type, polymer dispersed liquid crystal (PDLC) type, cholester It is formed by using liquid crystals, such as a lick type. A predetermined orientation is given to the liquid crystal layer 13.

The operation of the liquid crystal display device 10 of the above-described structure will be described.

In the white mode, light incident on the display surface passes through the insulating substrate 29, the color filter 30, the transparent electrode 31, and the liquid crystal layer 13 to reach the surface of the reflective electrode 19.

Since the unevenness is formed on the reflective electrode 19, incident light is scattered and reflected by the unevenness. The reflected light passes through the liquid crystal layer 13, the transparent electrode 31, the color filter 30, the insulating substrate 29, and the polarizing plate 32, and returns to the outside as display light.

On the other hand, in the black mode, incident light is reflected by the reflective electrode 19 as in the white mode, but is not output to the outside because it is blocked by the polarizing plate 32. In this way, the on / off operation of the liquid crystal display device 10 is performed.

The manufacturing method of the reflective film (lower substrate 11) of the liquid crystal display device will be described. 2 (a) to 2 (d) show manufacturing steps.

First, each TFT 16 as a switching element is formed on the insulating substrate 14. That is, the gate electrode 20 is formed on the insulating substrate 14 and an insulating protective film 15 covering the gate electrode 20 is then formed. Next, a semiconductor layer 21 having a drain region and a source region, not shown, is formed on the insulating protective film 15 by etching, impurity doping, or the like. Then, a drain electrode 22 and a source electrode 23 in contact with the drain region and the source region, respectively, are formed on the insulating protective film 15. In addition, a passivation film 17 is formed and patterned on the TFT 16 to have a structure as shown in Fig. 2A.

Next, the polyimide is coated on the surface of the structure and calcined to form a flat polyimide film 35 having a thickness of, for example, 3 mu m (Fig. 2 (b)). Firing is carried out, for example, at a temperature of 90 ° C. for 10 minutes.

Subsequently, laser ablation is performed on the polyimide film 35 to form an organic insulating layer 18 having contact holes 18a and unevenness 18b, as shown in FIG.

3 shows the structure of an optical processing system 40 used in laser ablation. The optical processing system 40 shown in FIG. 3 includes a light source 41, a shaping section 42 and a mask 43.

The light source 41 emits a pulsed laser beam, for example a KrF excimer laser beam (wavelength 248 nm). The laser beam is irradiated with an intensity that can secure a predetermined number of pulses and a good ablation profile. For example, the laser beam is irradiated with the intensity that the energy density irradiated to the portion of the polyimide film 35 on which the contact hole 18a is to be formed is 300 mJ / cm 2.

The shaping portion 42 includes a flyeye lens, a cylindrical lens, a mirror, and the like, and shapes the pattern of the laser beam into a flat top profile as shown in FIG. 4. The molded laser beam is irradiated almost vertically, for example, toward the target polyimide film 35.

Since the mask 43 is located between the molded part 42 and the object to be irradiated, the laser beam emitted from the molded part 42 is irradiated to the polyimide film 35 which is an irradiation target through the mask 43. The surface of the polyimide film 35 irradiated with the laser beam is lost (removed) by ablation.

The mask 43 is composed of a so-called dielectric layer capable of adjusting the light transmittance to a predetermined transmittance. That is, the mask 43 is constituted by forming a dielectric film (not shown) patterned in a predetermined shape on a transparent substrate such as quartz.

The dielectric film is composed of, for example, a film such as SiO ₂ , Al ₂ O ₃ , HfO ₂ , YF ₃ , MgF ₂ , LaF ₃ , ThF ₄ , or a laminated film of these films, and is formed on a substrate by a conventional film deposition method. Is formed. The dielectric film is provided like an island on the surface of the substrate in a predetermined shape using a conventional patterning method. The dielectric film has, for example, a substantially planar shape. The islands of the dielectric film are formed to a predetermined thickness to achieve a predetermined light transmittance. By setting each of the material and thickness of the dielectric film on the mask surface to a predetermined distribution, a predetermined light intensity (energy density) can be achieved on the irradiation surface.

Since the degree of ablation varies in proportion to the energy density level, the dielectric film can be removed to different depths. Specifically, the dielectric film is not provided in the region corresponding to the contact hole 18a, but the dielectric film is provided to a predetermined thickness in the region corresponding to the portion where the unevenness 18b is to be formed. By irradiating a laser beam through the mask 43 thus formed, the contact holes 18a and the unevenness 18b may be formed in and on the polyimide film 35. The depth of ablation can be adjusted by the number of pulses of the laser beam that are irradiated.

The laser beam passes through the mask 43 and is shaped, for example, from the profile shown in FIG. 4 to the profile shown in FIG. 5. By irradiating the molded laser beam, the contact holes 18a and the unevenness 18b can be formed in and on the polyimide film 35 as shown in FIG. 1.

In the profile shown in Fig. 5, the laser beam irradiated to the portion where the contact hole 18a is to be formed has a flat shape without being weakened by the dielectric film. As mentioned above, the energy density of the laser beam is set to a value capable of sufficiently forming the polyimide film 35 having a predetermined thickness. The energy density of the flat portion corresponding to the portion where the contact hole 18a is to be formed is, for example, 300 mJ / cm 2.

On the other hand, the profile of the energy density corresponding to the portion where the unevenness 18b is to be formed represents a plurality of peak values, at least four peak values (maximum value or minimum value) within the above-mentioned range. The peak value is in the range of, for example, 60 mJ / cm 2 to 200 mJ / cm 2.

In this way, the irradiation of the laser beam having a plurality of peak values of the profile forms the unevenness 18b having a bottom portion and an upper portion corresponding to the peak value in the polyimide film 35. Since the profile has four or more peak values, the unevenness 18b to be formed has four or more heights.

When a laser beam having a predetermined intensity distribution is irradiated onto the polyimide film 35 through the mask 43 in the same manner as described above, as shown in FIG. The organic insulating layer 18 which has is formed.

Patterning using ablation provides a gentler shape compared to patterning using conventional lithography techniques. Thus, unlike in the case of using photolithography techniques, annealing is not essential. However, if necessary, it may be carried out at a temperature of 250 ° C. for one hour to smooth the unevenness 18b on the substrate.

After formation of the organic insulating layer 18, for example, an aluminum film is formed on the organic insulating layer 18 and then patterned to form the reflective electrode 19 as a reflective pixel electrode (Fig. 2 (d)). ). The lower substrate 11, which is a reflective film, can be manufactured in the manner described above.

A spacer (not shown) is positioned between the lower substrate 11 and the counter substrate 12 on which the color filter and the like are stacked on the insulating substrate 14, and the liquid crystal 13 is filled in the space (cell) formed by the spacer. It is sealed. Then, the polarizing plate 32 is attached by adhesion or the like to produce the reflective liquid crystal display device 10 shown in FIG.

According to this embodiment, as described above, a plurality of stages of unevenness 18b having at least four heights are formed on the organic insulating layer 18 by laser ablation. The multiple unevenness 18b of the organic insulating layer 18 forms the uneven surface having low regularity on the upper reflective electrode 19. This achieves a reflective film and a liquid crystal display device 10 having high light scattering properties and excellent display properties.

The uneven portions 18b of the plurality of stages of the organic insulating layer 18 are formed by irradiating a laser beam onto the organic film through the mask 43 having a predetermined transmittance distribution. The transmittance distribution of the mask 43 can be arbitrarily set, and the height of the unevenness 18b can be easily set to a plurality of stages by adjusting the transmittance distribution and the number of irradiation pulses.

Since the polyimide film 35 is directly processed by laser ablation, the reflective film and the liquid crystal display device can be manufactured in a substantially small number of processes. That is, in the case of using a conventional photolithography technique, a step of forming, exposing and developing a resist film and an organic film is required on the upper side, but in the case of using ablation, the contact hole 18a and the unevenness ( An organic insulating layer 18 having 18b) may be formed in at least one step.

Further, in the photolithography process, the unevenness 18b has a steep shape, which requires annealing. However, in the ablation method, the surface of the unevenness 18b is relatively smooth. Thus, annealing does not necessarily have to be performed, and as a result, the organic insulating layer 18 can be formed in a much less process.

The first embodiment uses a so-called dielectric mask having a so-called dielectric film. However, the mask 43 is not limited to this type, and may be any type as long as the light transmittance can be controlled as necessary.

Although the contact holes 18a and the unevenness 18b are formed at the same time in the ablation step, they may be formed in separate processes using different masks.

Second embodiment

The manufacturing method of the reflecting film according to the second embodiment will be described. In order to easily understand the second embodiment, the small components corresponding to the elements of the first embodiment will be given the same reference numerals and the description thereof will be omitted.

In the second embodiment, unlike the first embodiment, the mask 43 is not used and scanning irradiation is performed with a spot-like shape laser beam so that the organic insulating layer ( 18, the unevenness | corrugation 18b etc. are formed on it. Hereinafter, the manufacturing method according to the second embodiment will be described.

In the embodiment to be described below, the organic insulating layer 18 is formed to a thickness of 3 μm by baking the acrylic resin at 150 ° C. for one hour.

The laser beam used in the second embodiment has a spot shaped profile representing the Gaussian distribution shown in FIG. The energy density of the laser beam at the top of the spot shape profile is set within a predetermined range.

The spot laser beam is irradiated to the target (substrate) using a device similar to that used in the first embodiment. The substrate is for example located at the X-Y end and is movable in the plane. During laser processing, the substrate is moved intermittently in a predetermined pattern. The laser beam is irradiated with a predetermined number of pulses in synchronization with the movement of the substrate. Other structures may be used that irradiate a scanning laser beam against a fixed target substrate.

On the surface of the acrylic resin film irradiated with the laser beam, the acrylic resin in the irradiated portion is burned out by sublimation. The energy density of the laser beam to be irradiated and the number of pulses are adjusted for each predetermined area. By performing irradiation while changing the laser beam intensity, it is possible to form the contact holes 18a and the unevenness 18b having a plurality of depths in and on the organic insulating layer 18.

In the embodiment of ablating acrylic resin, for example, an XeCl excimer laser beam (wavelength 308 nm) whose profile has a diameter of 5 mu m phi at half width can be used. In this case, as shown in Fig. 2C by irradiating a predetermined number of pulses of a laser beam with multiple values such that the energy density at the top of the profile lies in the range of 40 to 190 mJ / cm 2, for example. As described above, a plurality of stages of unevenness 18b having four or more height values may be formed on the surface of the acrylic resin film. In addition, the contact hole 18a may be formed by, for example, irradiating 8 pulses of a laser beam having an energy density of 300 mJ / cm 2 at the top of the profile.

According to the second embodiment, as described above, the multi-stage unevenness 18b and the contact hole 18a irradiate the pulses of the required number of spot laser beams while relatively moving the laser beam in a predetermined pattern. As a result, the organic layer may be formed on and in the organic layer. It is apparent that the second embodiment provides the same advantages as the first embodiment.

In the second embodiment, the target substrate is moved, but instead, an irradiation port for the laser beam may be moved.

Third embodiment

A third embodiment will be described in conjunction with the accompanying drawings. In order to more easily understand the third embodiment, the same reference numerals are given to the same elements as those of FIG. 1 and the description thereof will be omitted.

Fig. 7 shows the structure of the reflective film (lower substrate 11) according to the third embodiment. The reflective film according to the third embodiment is used in a so-called non-transmissive liquid crystal display device having a function of both a reflection type and a transmission type.

As shown in FIG. 7, the reflective film 11 according to the third embodiment includes a reflection area 51 and a transmission area 51.

The reflective electrode 19 is formed on the reflective region 50 of the organic insulating layer 18. Multiple stages of unevenness are formed on the surface of the reflective region 50.

The transparent electrode 52 of indium tin oxide (ITO) is formed on the organic insulating layer 18 of the transparent region 51. The surface of the organic insulating layer 18 in the transmission region 51 is formed almost flat. The transparent electrode 52 is also flat. The transparent electrode 2 is in contact with the reflective electrode 19 to be electrically connected. An insulating layer separating the two electrodes 52 and the reflective electrode 19 is provided therein, and a structure in which the transparent electrode 52 and the reflective electrode 19 are connected to each other through the contact hole 18a may be used instead.

The liquid crystal display device 10 equipped with a reflective film having a reflective electrode 19 and a transparent electrode 52 functions as a so-called non-transmissive liquid crystal display device having functions of both a reflective type and a transmissive type.

The reflective film 11 shown in FIG. 7 can be manufactured in the same method as used in the first embodiment. This method is described below with reference to Figs. 8A to 8D.

First, a substrate having a TFT 16 is provided as shown in Fig. 8A. Next, a polyimide film 35 is formed on the substrate as shown in Fig. 8B with a thickness of, for example, 2 mu m. For example, the polyimide film 35 is formed by firing at 110 ° C. for 10 minutes.

Then, as in the first embodiment, laser treatment is performed on the polyimide film 35 to form an organic insulating layer 18 having a shape as shown in Fig. 8C.

In a third embodiment, a laser beam with the profile shown in FIG. 9 is irradiated. The energy density of the laser beam is set in the range of 30 to 250 mJ / cm 2, for example, and the number of irradiation pulses is 10, for example.

As shown in FIG. 9, the profile of the laser beam passing through the mask 43 has a flat and stable energy portion and an uneven portion. Irradiation of the laser beam with the profile having the uneven portion and the flat portion forms the uneven portion and the flat portion on the polyimide film 35 as shown in Fig. 8C.

Next, for example, a chromium thin film is formed on the organic insulating layer 18, and then patterning as shown in FIG. 8 (d) is performed to remove the chromium thin film on the flat portion. A transparent electrode 52 such as ITO is formed on the exposed flat portion of the organic insulating layer 18. In this way, the reflective film shown in FIG. 7 is completed.

As described above, the third embodiment provides a reflective film having a reflective electrode 19 having a plurality of stages of uneven and flat transparent electrodes. The uneven portion and the flat portion of the organic insulating layer 18 on which the transparent electrode 52 and the reflective electrode 19 are to be formed may be formed in a single process by laser ablation. The reflective film shown in FIG. 7 and the non-transmissive liquid crystal display device 10 having the reflective film may be manufactured in a substantially reduced process.

In the first to third embodiments, the organic insulating layer 18 is formed of polyimide or acrylic resin. However, the organic insulating layer 18 may be formed of a resin having a predetermined light absorption range, such as a polyimide resin, an epoxy resin, an acrylic resin, a cyclic olefin or a novolak resin.

The laser ablation process may be performed by selecting a laser beam to be used depending on the type of organic material used as the organic insulating layer 18. Examples of available laser beams include, for example, ultraviolet rays of ArF laser (193 nm), KrF laser (248 nm), XeCl laser (308 nm) or XeF laser (351 nm), or YAG (Yttrium), for example. Aluminum Garnet) infrared laser (1.065 mu m) or carbon dioxide laser (10.6 mu m).

The present invention can be similarly adapted to a reflective film and liquid crystal display device using a stacker structure TFT (staggered structure TFT) or a so-called channel protection TFT.

Although the TFT 16 is used as a switching element, the present invention is not limited thereto, but an active matrix liquid crystal display device or a switching element using another switching element such as a metal-insulator-metal (MIM) element, a diode, or a varistor is used. It can be applied to a passive matrix liquid crystal display device which is not used.

Various embodiments and modifications have been described without departing from the spirit and scope of the invention. The above-described embodiments are intended to illustrate the invention and are not intended to limit the scope of the invention. The scope of the invention is indicated by the appended claims rather than the above embodiments. Various modifications encompassed by the claims of the present invention and equivalent to the claims should be considered to be within the scope of the present invention.

Claims (12)

delete delete delete In the reflective film manufacturing method, Forming an insulating layer 18, Irradiating a laser beam on the insulating layer 18 to form irregularities 18b on the surface of the insulating layer 18 by ablation; Forming an electrode 19 on the insulating layer, In the ablation step, the insulating film 18 is irradiated with the laser light having a flat profile through the mask 43 composed of a dielectric layer capable of adjusting the light transmittance to a predetermined transmittance distribution. . In the reflective film manufacturing method, Forming an insulating layer 18, Irradiating a laser beam on the insulating layer 18 to form irregularities 18b on the surface of the insulating layer 18 by ablation; Forming an electrode 19 on the insulating layer, The method of manufacturing a reflecting film, characterized in that in the ablation step, the laser light having a spot shape is moved while varying intensity to irradiate the insulating layer (18). The method according to claim 4 or 5, In the ablation step, the laser beam is a reflection film manufacturing method, characterized in that irradiated in a pulse shape. The method according to claim 4 or 5, In the ablation step, the unevenness (18b) is formed by a process to have a height level of four or more. The method according to claim 4 or 5, The switching element 16 is provided below the insulating layer 18, A method for manufacturing a reflective film, characterized in that a contact hole (18a) exposing one end of the switching element (16) is formed in the ablation step. The method according to claim 4 or 5, In the ablation step, a flat portion is formed on the insulating layer 18 together with the unevenness, And forming a transparent electrode (52) on the flat portion. The method according to claim 4 or 5, And annealing the insulating layer (18) after the ablation step. delete delete

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